#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
int main()
{
    int i = 0, count = 0, j;
    for (i = 100; i <= 999; i++) 
    {
        for (j = 2; j < i; j++) 
        {
            if (i % j == 0) 
            {
                count++;
                break;
            }
        }
    }
    printf("%d\n", 900-count);
    return 0;
}